had better, had rather, would (had) rather,
would (had) rather … than
1）had better可缩成’d better，表示对人的劝告建议，但不宜用于陌生人及同长辈的交谈中，后跟动词原形，其否定式是not放在动词之前，并可用于被动语态。如：
You’d better go at once. 你最好马上走。
You’d better not go. 你最后不去。
Breakfast had better be eaten before six o’clock. 早饭最好在六点前吃。
2）had rather（＝prefer to），也可缩成’d rather，表示句子主语的愿望、选择，后跟动词原形，其否定式是not放在动词之前，不能用于被动语态。如：
I had rather go at once. 我宁愿马上去。
I’d rather not accept your advice. 我宁愿不接受你的劝告。
I’d rather stay at home than go to the cinema. 我宁愿呆在家里而不去看电影。
3）后两者在陈述句中可以通用，而在疑问句中，习惯上用would，不用had。would (had) rather是习惯用语，表示“宁愿，宁可”，后接动词原形或that从句，从句动词用过去时的虚拟语气，表示现在或将来。如：
I would (had) rather not go. 我宁可不去。
I would (had) rather she went on Sunday. 我宁愿她星期天去。
would (had) rather … than是“宁愿…也不”的意思，than是连词，后接省略了的状语从句。如：
Liu Hulan would (had) rather die than give in before the enemy. 刘胡兰在敌人面前宁死不屈。
